Electric lamp mount



Dec. 27, 1960 H. S. STRAUSS ELECTRIC LAMP MOUNT Filed June 18, 1959 INVENTOR.

United States Patent O ELECTRIC LAMP MOUNT Herbert S. Strauss, Fort Lee, NJ., assignor to Duro-Test Corporation, North Bergen, NJ., a corporation of New York Filed June 18, 1959, Ser. No. 821,269

8 Claims. (Cl. S13- 25) This invention relates broadly to improvements in the mounting for the light generating unit of electric lamps of higher wattages, especially those of higher than 100 watts.

A broad object of this invention is to provide an eiective mounting structure for such lamps which does not require a so-called top support which is usually in the form of a deformation of the top of the envelope in which a resilient support member engages.

Broadly speaking the invention comprises a leverage system for supporting the light generating unit, wherein the fulcrum is intermediate the ends of the leverage system so that the light generating unit lies on the one side of the fulcrum and a resilient counterbalancing means is secured to the leverage system on the other side of the fulcrum and reacts against the lamp envelope.

In accordance With this invention the light *generating l unit which may be a relatively heavy mercury vapor lamp either alone or in combination with a ballasting resistor in the form of a lament is supported on a leverage system and is the source of torque producing forces when the lamp is subjected to shock. This leverage system in accordance with this invention is provided with counter torque producing elements in the form of flexible or resilient members which bear on the light transmitting envelope forming part of the lamp.

Such an arrangement has a number of advantages, including a relatively simple mechanical structure suited to machine assembly procedures. Another advantage is that the top support for the lighting unit commonly used in heavy wattage lamps of this type is not required. T his top support commonly takes the form of a deformation in the lamp bulb in which a top supporting fixture secured to the adjacent end of the lighting unit is seated. Experience has demonstrated that under excessive shock this top supporting tixture sometimes escapes from its seat, causing permanent distortion of the mount.

An additional advantage of this arrangement is that it provides complete freedom of longitudinal and transverse movement due to thermal expansion and contraction. The resiliency of a mount in accordance with this invention permits it to yield in any transverse direction under shock and to be restored by the counter torque producing element While minimizing the stresses and strains on the mount.

Finally the mount retains its centering under all normal shock forces, avoiding permanent disguration thereof as might be the case with a top `supported arrangement replaced by this invention.

Other and more detailed objects of the invention will be apparent from the following description of the form of invention selected for illustration herein.

In the accompanying drawings:

Figure 1 is an elevational view of a self-ballasted mercury vapor lamp of larger size constructed in accordance with this invention showing the light transmitting envelope in cross-section;

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Figure 2 is a view at right angles to the view of Fig. 1 with most of the envelope broken away;

Figure 3 is a cross-sectional View taken on the line 3 3 of Fig. l; and

Figure 4 is a diagrammatic circuit illustration showing the manner in which the parts are electrically connected.

As will appear to those skilled in the art from the following description of the embodiment of the invention selected for disclosure purposes the subject matter of the invention can be applied not only to self-ballasted mercury Vapor lamps, but also to externally ballasted mercury vapor lamps, high wattage incandescent lamps and various combinations thereof. Indeed, although not illustrated in the drawings, the lamp illustrated therein may be provided with a reiiector or a iluorescent coating, thereby providing a combination arc, incandescent and iuorescent lamp.

The light transmitting envelope may take the form of spherical section 11 having an elongated cylindrical neck 111a of reduced diameter to the end 0f which is attached a mounting fixture such as the screw base 13. The envelope has a re-entrant stem 8 in which is mounted, in accordance with common practice a tubulation tube 8ab and at the upper end of which stem there is formed the usual press 8b. Sealed in the press are a pair of right angled support rods 9 and 10, to which are respectively secured by welding intermediate the ends thereof, a pair of support rods 6 and 2. These rods extend in generally parallel relation longitudinally of the bulb and are made preferably of metal suited to the purpose having sufficient resiliency. The supports 9 and 10 provide fulcrums for the rods 6 and 2 and are rigidly iixed in the press of the stem. The supports 9 and 10 are respectively provided with conductive'leads 9aq and 10a, the former of which is in turn connected to the threaded metal base 13 and the latter of which is connected to the center contact button 10b mounted on the base in accordance with usual practice. Although not illustrated, it Will be understood that the usual hermetic seal is effected in the press by the use of sealing in wires of the proper thermal characteristics.

Welded or otherwise attached to the upper end of lthe rod 2, in parallel spaced relation are a pair of metal straps 3 and 4 of suitable configuration in which the reduced ends 1a and 1b of the mercury vapor arc tube 1 are secured. The upper electrode 3b of the arc tube is connected by a conductive pigtail 3a to the bracket 3. The electrode 3 at the other end of the are tube is connected by a conductive pigtail 3d to one end of a ballasting resistor 15 in the form of a light emitting iilament. The lament 15 is supported at the outer end of a series of supporting wires 7, the other ends of which are sealed in a glass ixture 5, also supported by the strap 4. The upper end of the support rod 6 is seated in the glass xture 5, as shown. The jumper 3d is connected to the end of the support wire 7, which is indicated in Fig. 2 by that reference numeral. The lefthand support wire 7 of Fig. 1 is electrically connected to a jumper 6a, which is welded to the upper end of the rod 6. A supporting electrode 3e for the arc lamp is connected in series with the support rod 2 through a starting resistor 14.

The lower ends of the rods 2 and 6 which project below the supports 10 and 9 are provided with a pair of resilient straps 12, the ends 12EL of which are shaped to seat at spaced points on the inner surface of the neck 11a, as clearly indicated in Fig. 3.

For the sake of completeness, the complete circuit provided by the above connections is diagrammatically illustrated in Fig. 4, where the corresponding parts of the circuit are given the same reference numerals as in the other gure. As a result the lament 15 is shown to be in series with the arc lamp 1 when starting resistor 14 is in parallel with Ithe arc path.

Upon consideration it will be seen that the objects of this invention are attained by this construction. The relatively heavy lighting unit consisting of .the arc lamp 1 alone when the lamp is externally ballasted, or the lamp l and the filament 15 in the self ballasted type of lamp is supported to one side of the fulcrum points provided by the supports 9 and 10. The resilient bearing members 12 which engage the neck 11al of the bulb are on the other side of the fulcrum points.

Those skilled in the art will appreciate that the dimensioning of the parts will be determined in such a manner as to provide the proper counter-torque to absorb the forces produced on the lighting unit side of the assembly when the lamp is shocked. For larger lamp wattages, larger glass envelopes are used to maintain the wattagevolume relationship. The larger the envelope, the longer will be its neck. With larger and longer necks longer counter-torque lever arms can be provided to maintain the required balance with respect to the lighting unit side of the lamp, which will likewise be larger and heavier.

From the above description it will be apparent to those skilled in the art that the subject matter of this invention is capable of variation in detail while employing the real substance thereof, and it is preferred, therefore, that the protection afforded hereby be determined by the appended claims.

What is claimed is:

1. An electric lamp assembly comprising a light transmitting envelope, a pair of mount rods therein, fulcrum means for supporting each of said rods at a point intermediate its ends, a light generating unit secured to said rods so as to lie entirely on one side of said points, and resilient means secured to said rods on the other side of said points and engaging said envelope.

2. In the combination of claim 1, said envelope having a re-entrant stem and said fulcrum means being supported thereon.

3. In the combination of claim l, said light generating unit including an arc discharge tube.

4. In the combination of claim 1, said light generating unit including an arc discharge tube and a ballasting resistor.

5. In the combination of claim 1, said envelope includ ing a spherical and a reduced neck portion, said resilient means engaging said neck portion.

6. In the combination of claim 1, said envelope including a unitary bulb and neck, a re-entrant stem extending longitudinally of said neck and said fulcrum means being supported on the end of said re-entrant stem whereby said lrods extend longitudinally of said envelope into said bulb in one direction and into said neck in the other direction.

7. An electric lamp assembly comprising a light transmitting envelope having a reentrant stem extending along the axis of said envelope, a pair of support members mounted on said stem, a pair of mount rods lying parallel to the axis of said envelope and xed to said support members at points intermediate the ends of the mount rods, a light generating unit, means for supporting said unit on one side of said points, and resilient means secured to said mount rods on the other side of said points and uniting said envelope.

8. In the combination of claim 7, said envelope comprising axially aligned spherical and tubular neck portions, said light unit lying within said spherical portion and said resilient means engaging said neck portion.

References Cited in the le of this patent UNITED STATES PATENTS 2,042,148 Gaidies May 26, 1936 2,830,210V Jenne Apr. 8, 1958 2,904,710 Beeninga Sept. 15, 1959 

